Improvement in car-brakes



W. H. BROWNE & W. M. PEGRAM.

Car-Brakes.

No.- 136,581. Patented March 11, 1873.

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AM. PnoTa-umnsRAFH/c c0. MK (ossome macaw) UNITED STATES PATENT OFFIcn.

WILLIAM HAND BROWNE AND WILLIAM M. PEGRAM, OF BALTIMORE, MD.

IMPROVEMENT IN CAR-BRAKES.

Specification forming part of Letters Patent No. 136,581, dated March11, 1873.

To all whom it may concern:

Beit known that we, WM. HAND BROWNE and WM. M. PEGRAM, of the city ofBaltimore and State of Maryland, have invented a new Improvement inBrakes for Railroad Cars, of which the following is a specification:

The nature of our invention is fully represented in the accompanyingdrawing, to which reference is made.

A disk of iron or other suitable material,

fixed firmly at the lower end of the brake-rod, and having ahelix-shaped elevation or snail on the upper surface, grooved at theouter edge; said helix to comprise one whole turn, or only part of aturn, of a spiral in advancing from the axis to the circumference of thedisk, and to have whatever form of curvature shall be found mostsuitable in any given case. The chain of the brake is secured at theouter extremity of the helix, and winds in the groove as the brake-rodis turned; the advantage of this arrangement being that in the earlierpart of the movement, while taking up the slack of the chain andbringing up the brake to the wheel, as at Fig. 1, the movement shallproceed rapidly while, when thebrake is brought against the wheel andforce is necessary, the chain being then on the smallest part of thehelix, the greatest leverage is obtained, as in Fig. 2. Thus the wholeoperation of putting down the brake can be performed with part of a turnof the lever as effectively as and much more quickly than by thecontrivance now in use.

In Figs. 1 and 2 a fixed roller or pulley is shown, which guides thechain to the groove of the helix. Fig. 3 gives the plan, and Fig.

